Pile-driving and extraction apparatus

ABSTRACT

An apparatus for introduction of a vibro replacement column into a construction soil, having a tubular lance that is connected with a coupling part, on which at least two exciter cells are attached, distributed radially about the center axis of the lance. The cells each have a housing in which at least one shaft with at least one eccentric weight is disposed. The shaft is connected with a rotary drive. The exciter cells are oriented in such a manner that the eccentric weights of the exciter cells synchronize automatically during operation.

CROSS REFERENCE TO RELATED APPLICATION

Applicant claims priority under 35 U.S.C. §119 of European Application No. 12170034.8 filed May 30, 2012, the disclosure of which is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for introduction of a vibro replacement column into a construction soil.

2. The Prior Art

To increase the bearing capacity of a construction soil, it is known to improve it by using the method of vibro replacement. In this connection, so-called vibro replacement columns are introduced into the load-bearing regions of the construction soil. This is accomplished by setting a tube onto the construction soil and introduced all the way to the bearing soil, by means of a vibrator, so that the looser soil region is displaced laterally. The tube is filled with suitable material to be added, such as gravel or crushed stone, and subsequently drawn out, whereby material continuously exits from the end of the tube facing the soil, which material is further compacted by multiple alternate lowering of the tube. In this way, a column of the compacted added material is produced in the soil, and this is referred to as a vibro replacement column.

In the aforementioned method, a vibrator guided on a leader is placed against the tube to be introduced, and firmly connected with the tube. In practice, this connection is under stress from bending moments that occur as the result of lateral drifting of the tube in the soil. The vibrator transfers the bending moments to the leader by way of the guides with which it is connected with the leader. Therefore, the connection between vibrator and pipe, the guides between vibrator and leader, and the leader itself are under stress from the bending moments.

Furthermore, filling of the tube generally takes place only after introduction of the tube into the construction soil down to the bearing layer, because here filling by way of a funnel, by means of a backhoe or the like, is easiest. In this connection, filling is hindered by the vibrator used, which is situated above the funnel.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to create an apparatus for introduction of a vibro replacement column into a construction soil, which apparatus allows simplified handling of the tube as well as of its filling, and in which the connection between vibrator and tube is not under stress from bending moments. According to the invention, this task is accomplished by an apparatus for introduction of a vibro replacement column into a construction soil, having a tubular lance that is connected with a coupling part, on which at least two exciter cells are attached, distributed radially about the center axis of the lance. The cells each have a housing, in which at least one shaft with at least one eccentric weight is disposed, which shaft is connected with at least one rotary drive. The at least two exciter cells are oriented in such a manner that the eccentric weights of the exciter cells synchronize automatically during operation.

With the invention, an apparatus is created for pile-driving or extraction of a material to be pile-driven, particularly a vibro replacement lance, into or out of the soil, respectively, which allows simplified handling of the tube as well as its filling, and in which the connection between vibrator and tube or tubular lance is not stressed by bending moments that result from possible lateral drift of the tube in the soil. The at least two exciter cells that together produce a vibrator are connected with the tubular lance by way of a coupling part.

Furthermore, the at least two exciter cells are structured in such a manner that their eccentric weights automatically synchronize during rotation, specifically in such a manner that the vertical force components add up and eliminate the horizontal force components to a great extent. In this way, a resulting force essentially parallel to the direction of effect is achieved.

Preferably, exactly two exciter cells are provided, whereby preferably, each exciter cell is provided with a separate rotary drive, which is designed so as to rotate the at least one eccentric weight of each exciter cell.

In a further development of the invention, devices for stabilization of the synchronous operation of the at least two exciter cells are provided. For this purpose, electrical stabilizers can particularly be used. In this way, controlled adjustment of the exciter cells is made possible.

In an embodiment of the invention, the coupling part is connected with a carriage by way of which it is mounted to be displaceable along a leader. In this way, the apparatus, as a work device, can be coupled to the leader directly, without the need for further components.

In a further embodiment of the invention, the carriage is connected with a basic carriage guided on the leader, which can be impacted with tensile and/or pressure forces by way of a drive. In this connection, the basic carriage is preferably connected with the carriage in a resilient manner, by way of flexible elements, particularly elastomers. In this way, transfer of the vibrations generated by the exciter cells to the leaders is reduced.

In a further embodiment of the invention, a bracket is attached to the basic carriage, which is provided with the flexible elements, particularly elastomers, by way of which the bracket is connected with the carriage. In this way, it is possible to impact the goods to be pile-driven with a preload force or tensile force, which is applied by the leader, with simultaneous vibration damping.

In a further embodiment of the invention, a filling funnel is provided for filling the lance, which funnel is connected with the coupling part or the tubular lance by way of damping elements. By means of the configuration of such a one-part lance with an integrated filling unit, simple positioning and introduction of the lance into the construction soil is made possible, with simultaneous introduction of fill material into the lance. Preferably, the lance has a flange that is screwed onto a flange provided on the coupling part. It is advantageous if the funnel is furthermore connected with the carriage by way of damping elements.

In a further embodiment of the invention, the tubular lance is configured with a double wall. A connector for application of compressed air to the cavity formed between the two walls is preferably provided. During vibro replacement compaction of beds of bodies of water, a controllable increase in the buoyancy of the lance in the body of water is made possible, thereby making it possible to significantly reduce the tensile force to be applied by the support device. Particularly for construction soil improvement measures in bodies of water, the wall in such a further embodiment of the invention has lateral openings. These openings serve for exit of water displaced by replacement material that has been introduced. In this way, the vibro replacement process is further improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows a schematic representation of an apparatus for introduction of a vibro replacement column into the soil;

FIG. 2 shows the representation of the apparatus from FIG. 1 in a front view;

FIG. 3 shows the representation of the apparatus from FIG. 1 in a view from the rear, and

FIG. 4 shows the representation of the apparatus from FIG. 1 in a further spatial view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The vibro replacement apparatus chosen as an exemplary embodiment essentially consists of a coupling part 1, which is connected with a carriage 2 and provided with two exciter cells 3 that are disposed to lie opposite one another. The coupling part 1 is firmly connected with a tubular lance 4, and resiliently connected with a funnel 5 for filling the lance 4, opposite the lance 4. The coupling part 1 is guided on a leader 8, by way of the carriage 2, which is connected with the basic carriage 7 of the leader 8 by way of a bracket 6.

The coupling part 1 is formed by a base plate 11, configured to be essentially rectangular, which has a flange 12 in the center for attaching the lance 4. An inlet connector 13 is disposed on the base plate 11, opposite the flange 12, which connector is fixed in place on both sides by way of two vertical holding plates 14. These holding plates 14, together with the base plate 11, are simultaneously accommodations 15 for the exciter cells 3. The coupling part 1 is connected with the carriage 2 by means of weld connections.

The carriage 2 essentially consists of a block-shaped frame 21, which is provided, on its back side, with guide elements 22 for accommodating the leader rails 81. On its side opposite the guide elements 22, two wings 23 are furthermore affixed on the carriage 2, on the end side, lying opposite one another, projecting toward the outside, for resilient attachment of the funnel 5 by way of damping elements 51. The carriage 2 is resiliently connected with the bracket 6 by way of elastomer blocks 24 that lie opposite one another in pairs, within the frame 21, and the bracket passes through the frame 21 of the carriage 2 along the center axis of the latter.

The bracket 6 consists essentially of a rectangular profile, on which a connector piece 62 for a connection with the leader basic carriage 7 is provided, at the ends that lie opposite the carriage 2. The exciter cells 3 each comprise a housing 31, in which a rotatably mounted shaft-13 not shown—is disposed, which is provided with an eccentric weight—not shown. The shaft is connected with a rotary drive 32, which is attached to each housing 31. The exciter cells configured in this manner are attached on the base plate 11 of the coupling part 1, on both sides of the inlet connector 13, lying against the holding plate 14 assigned to them.

In the exemplary embodiment, the lance 4 is configured as a cylindrical tube, with a flange 41 formed onto its end that faces the coupling part 1. The flange 41 is screwed onto the flange 12 of the coupling part 1.

The funnel 5 is connected with the inlet connector 13 by way of damping elements 51, and with the frame 21 of the carriage 2 by way of elastomer blocks 24.

The basic carriage 7 is connected with the connector piece 62 of the bracket 6 by way of a bolt latch 71. Accommodation plates 72 for attachment of tensile cables—not shown—are affixed on both sides of the bolt latch 71 on the basic carriage 7, by way of which the basic carriage 7 can be impacted with pressure or tensile forces.

Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

What is claimed is:
 1. An apparatus for introduction of a vibro replacement column into a construction soil, comprising: a tubular lance; a coupling part connected to the tubular lance; at least two exciter cells attached on the coupling part, distributed radially about a center axis of the lance, said cells each having a housing in which at least one shaft with at least one eccentric weight is disposed; and at least one rotary drive connected with the at least one shaft, wherein the at least two exciter cells are oriented in such a manner that the eccentric weights of the exciter cells synchronize automatically during operation.
 2. The apparatus according to claim 1, wherein the at least two exciter cells consist of exactly two single-shaft exciter cells.
 3. The apparatus according to claim 1, further comprising a stabilizing device for stabilization of the synchronous operation of the at least two exciter cells.
 4. The apparatus according to claim 1, wherein the coupling part is connected with a carriage, by way of which the coupling part is displaceably mounted on a leader.
 5. The apparatus according to claim 4, wherein the carriage is connected with a basic carriage guided on the leader, and wherein the carriage is adapted to be impacted with tensile or pressure forces by way of a drive.
 6. The apparatus according to claim 5, wherein the basic carriage is resiliently connected with the carriage by way of flexible elements.
 7. The apparatus according to claim 6, wherein a bracket is attached to the basic carriage, which bracket is provided with the flexible elements for connecting to the carriage.
 8. The apparatus according to claim 1, further comprising a filling funnel for charging the lance, said funnel being connected to the lance by way of damping elements.
 9. The apparatus according to claim 8, wherein the lance has a flange that is screwed onto a flange on the coupling part.
 10. The apparatus according to claim 1, wherein the tubular lance is configured with a double wall.
 11. The apparatus according to claim 10, further comprising a connector for impacting a cavity formed between the two walls of the tubular lance with compressed air.
 12. The apparatus according to claim 1, wherein the lance has a wall with lateral openings. 